Length of fluid simulation on a high end machine

Hello!
I’m trying to bake a fluid simulation and I’m getting some “?weird?” behaviour.

The scene is a simple cube with a inflow object on it pointing up to make a fountain.

When doing test bakes at 64 res it took around 2 secs per 1%. After everything seemed fine I tried to render at 512 res as I thought my machine could do it in a few hours. This ended up taking like a half an hour for 1% and BSODing whole PC soon after that.
After a reboot, the project file took longer than usually to open and changing res freezed blender for a minute or so.
Next bake was at 256 res and took solid 10 minutes to go from 0 to 1%, after that it took + - 3 min per %.
I tried even a 128 res and again, 0 to 1% took few minutes and after that it was something around 2-3min per 1%.

Is this normal for sim baking to take this long and crash at high res, or am I messing up?

PC specs and simulation settings

  • Intel i9-12900k
  • MSI RTX 3090 Gaming X Trio
  • Corsair 32GB DDR5 5200MHz CL38
    image

Thanks.

I would say it’s not unexpected it would do that. Remember that the resolution affects 3 axes, which means that every time you double it, it takes 8 times the resources. So, going from 64 to 512 is 8x8x8, so you get 512 times the amount of cells compared with the 64 res.

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I will also add: this is exactly why the fluid simulator has a feature to create spray/foam/bubbles particles. Those are used to add fine detail that the base simulation could never contain and allows creating massive simulations.

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Thanks for the feedback!
So is there some guideline for this?
Would fountain with water falling on inself with alot spray and foam require something like 128 res, and let’s say a close up of wine pouring in a glass use above 300 res as it needs to be more detailed?
Or am I still overshooting it?

Normally, the behavior of the water will be determined by the scale of the domain (so it’s important to model everything at an accurate scale) and the resolution will only determine the quality level. The resolution you use will be decided much more by the needs of your scene than by the type of water.

I should add that the mesh creation settings are also very important for the final look. The mesh has its own quality setting (upres factor) and also particle radius that needs adjustment. Those settings can affect the look of the simulation a lot. I would suggest adjusting those at a lower res for quicker testing, make sure the mesh settings allow every particle to be included in the mesh and that they don’t look like a bunch of obvious spheres.

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Thank you so much, this really helped me understand the simulation process better.